Tissue material phase transitions & embryo pattern formation

• Applicant: Professorin Dr. Nicoletta Petridou, Ph.D.
• Subject Area: Developmental Biology ; Biophysics ; Cell Biology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 518354236

Emergent collective properties are hallmarks of complex systems, where their macroscopic behaviour cannot be directly inferred by the behaviour of their microscopic building blocks. Embryonic development is a paradigmatic case of complex system: Tissue-scale behaviours emerge from microscopic molecular and cellular interactions. The development of various multicellular systems including tumours, organs, and embryos, rely on a fundamental macroscopic property, the tissue material state. It has been shown that tissue material states actively undergo dramatic shifts during development, resembling phase transitions in physics. Whether this emergent property --which exists only at the tissue level-- actively regulates other developmental processes or if it is an epiphenomenon arising from unavoidable cellular changes, is unknown.The underlying hypothesis of this project is that there is a causal feedback between the emergent material tissue state and the embryonic process of cell fate specification. To test this hypothesis, we aim to: i) disentangle the core cellular mechanism defining tissue material properties, ii) develop tools to precisely control the emergent tissue material state based on the identified cellular mechanism, and iii) mechanistically explore how the material state influences cell fate specification. We will thus need a methodology that specifically targets the tissue-scale state of the (zebrafish) embryo. To that end, we will build on our previous collaboration, where we generated a framework that quantitatively probes tissue material phases within the living organism both in space and time, and can therefore be combined with embryological techniques to address cell fate acquisition. We aim to combine cell and developmental biology experimental tools, optogenetic engineering, computer simulations and concepts of network theory and statistical physics.The synergy between different disciplines will provide a deeper understanding of the mechanisms underlying emergent collective behaviours in development. It will imply a methodological advance for the field of tissue dynamics, generating novel computational and experimental tools relevant for a wide range of multicellular systems. It will further set up a unique example of how to quantitatively link scales in biology. Finally, being able to control tissue-scale emergent properties will open possibilities for the fields of organ development and regenerative medicine

• DFG Programme: Research Grants
• International Connection: Austria
• Cooperation Partner: Professor Dr. Bernat Corominas-Murtra